Amorphization induced by deformation at ferrite-cementite nanointerfaces in a tribolayer and its effect on self-lubricating

Here, new insight into amorphization induced by deformation at ferrite-cementite nanointerfaces in a tribolayer is put forward, and an atomistic investigation into interfacial effects on amorphization is carried out using molecular dynamics (MD) simulations and spherical aberration-corrected high-resolution TEM (HRTEM) characterization. Nanoamorphous particles mix with oxide particles attached to the wear surface, which provide a lubrication state during dry sliding friction of pearlite steels. HRTEM images and energy-dispersive X-ray spectroscopy (EDS) maps show alternating ferrite-amorphous-ferrite lamellar features in the tribolayer. MD simulation results show that ferrite-cementite nanointerfaces with the Bagaryatskii orientation play important roles in the above amorphization, which can be exposited by the deformation response between the ferrite and cementite being inconsistent. A high density of dislocation defects destroys the ferrite-cementite interfaces to create an amorphous nucleation region, and after nucleation, the amorphization will expand into the cementite. This study lays the theoretical basis for revealing the mechanism of cementite amorphization in the tribolayer and will provide new ideas for designing and manufacturing amorphous self-lubricating films or solid materials. (C) 2020 The Author(s). Published by Elsevier Ltd.